Question

x, y and z are three sums of money such that y is the simple interest on x and z is the simple interest on y for the same time and same rate. Which of the following is correct?

• A. $xyz=1$
• B. $z^2=xy$
• C. $x^2=yz$
• D. $y^z=zx$

Answer 1

The correct option is A $xyz=1$

$\begin{array}{c}yissimpleinterestofxandZissimpleinterestofYatsometimeandRate,then.\\ y=\frac{x+r+t}{100}......................\left(i\right)\\ z=\frac{y\times r\times t}{100}........................\left(ii\right)\\ Dividingequation\left(i\right)by\left(ii\right)\\ \frac{y}{z}=\frac{\frac{x\times r\times t}{100}}{\frac{y\times r\times t}{100}}\\ y=\frac{x}{y}\\ y^2=2x\end{array}$